All Our Tomorrows
by Griever11
Summary: 'Today was a 'dark' day. It didn't really matter anyway. Measuring time was inconsequential when she lived her life one breath of air at a time.' A Castle apocalypse-ish AU, post Season 4. One shot. Caskett.
A Castle apocalypse-ish AU one shot, set anytime after season 4 I suppose. This is a little bit on the sci-fi side, so if you're not into that genre, you might not enjoy this. But if you're not too averse to the idea, please give this a read!

* * *

Something crunched under Beckett's foot and she cringed, stilling for a few seconds as she assessed her surroundings. Despite the startling crackle of broken glass, nothing else seemed amiss. Everything remained quiet, a deafening silence that brought on an uncomfortable ringing in her ears. Lifting her foot carefully over the bits of glass, she continued on, creeping further through the dark hallway, fingers tight around the handle of her knife.

The building must have been a school before The Cull. The hallway was littered with lockers, the metal rusted from years of neglect and decay. Old, rotting wood that probably used to be doors were scattered over the floor, black from ash and soot. Beckett pulled up the collar of her turtleneck, covering her nose in fear of inhaling remnants of Dust that could still be in the air.

Maybe this wasn't such a good idea. She doesn't know how much of the radioactive particles she'd inhaled entering the building and only time will tell if she'll descend into the madness caused by Dust poisoning.

She turned around as she contemplated her next move. She could go back out the way she came into the Safety Zone but that meant risking not having shelter for the night. Or she could proceed into the dark unknown of the abandoned school and maybe have the first good night of sleep in weeks.

The closest safe house she knew of was in New York - or what remained of it, anyway. At least half a day's walk from her current location and she shuddered at the idea of making the journey through the night. Her body was almost at its limit, every muscle screaming at her to stop and rest. She'd been walking for days, dodging the Synth patrols rounding up the remaining survivors and the constant vigilance was finally taking its toll on her.

Decision made, she swiveled around and ventured deeper into the school.

* * *

Beckett had lost all sense of time months ago, back when the Synths started experimenting with artificial life forces, so she didn't know how long she'd been creeping about in the school. Some days there would be daylight for hours and hours and then sometimes she'd be cloaked in darkness for what seemed like weeks on end. Today was a 'dark' day. It didn't really matter anyway. Measuring time was inconsequential when she lived her life one breath of air at a time.

Eventually, the hallway came to an end and she turned right, entering a large area that maybe had been a cafeteria in its past life. The first thing she noticed was that the air smelled cleaner here, and her senses went on high alert. Purified air meant Synths had been around and Synths being around meant _bad_ news.

With her heart thundering in her ears, she sheathed her knife and reached for the sabre strapped to her thigh that she usually saved for dire situations. The weapon had belonged to a Synth she'd disabled when she first woke up to the desolation caused by The Cull. Despite having had it for a long time, she still felt the same uneasiness that had coursed through her veins the first time she laid her hands on it. Using an enemy's weapon shouldn't feel as comfortable as it did.

The weapon vibrated in her hand and she pushed down on the button on the side of the sleek hilt. A bright orange glow of light burst from the top of the hilt and not for the first time, it pulled at some sort of memory that she once again couldn't quite seem to hold on to.

The fiery light crackled in front her, sizzling as it sliced through the air. The warmth that spread down her hands was inviting, a welcome source of heat to fight the freezing cold that had long enveloped the world.

She swallowed her fears and forced herself to move and explore the rest of the cafeteria so at the very least she can claim the area as hers to sleep in for the night. The glow from the sabre lit up most of the hall and as her eyes adjusted to the light. The hall was empty as far as she could tell and nothing seemed out of the ordinary. It calmed her racing heart and her thumb hovered over the button again, about to disengage her sabre.

Until she heard it.

The tell-tale whirr of a Synth turret idling.

The sabre flared yellow, picking up on the rush of nervousness through her. It was one of the reasons she never liked the weapon. The moment she'd laid hands on it, it felt like she'd claimed more than just physical ownership of the unassuming object. The color of the light that sparked from the polished, yet understated curved handle depended on her mood, and the fact that the weapon could pick up on her feelings never failed to creep her out.

Never mind the fact that it was a _Synth's_ weapon.

The turret, she realized, was hiding in a dark corner of the cafeteria. Instead of the bright red warning light that indicated it was armed and ready to fire, it remained idling and it set her heart at ease. Maybe it had already been deactivated. She inched toward it, sabre light now a gentle green as curiosity got the better of her.

Never having seen one up close before, she reached out to inspect it - maybe she could salvage it for parts, trade it in for some food later. The solid metal body whirred on, no sign of it coming to life and with a little more bravery, she ran her fingers over the-

"Wouldn't do that if I were you."

Startled, Beckett spun around, yellow heat crackling from the hilt of her sabre.

A man.

A man in fatigues and leather, clean shaven, frowning, pointing a gun straight at her head.

Only, as they kept staring at each other in a silent battle of wills, with every fibre of her being ready to fight, the expression on his face started to shift. His mouth fell open, eyes widening as he gasped, stumbling backwards.

"Beckett..."

The hushed surprise in his voice as he uttered the name she thought only _she_ knew stunned her.

Yet the gun remained trained at her head.

"Who are you?" she demanded, thrusting her sabre in front of her, dropping into a fighting stance. She wasn't taking any chances. She ignored the nagging feeling in the back of her mind, the odd feeling like she was forgetting something important, and instead focused on the gun in his hand, cocked and ready to fire.

"Who are you and how do you know my name?"

The man licked his lips and she could see his bravado slipping, shifting his weight from one foot to another. He swallowed and brought his other hand up to steady the arm pointing the gun at her. "Lower your weapon, Beckett. Please. It's me, Castle."

Beckett shook her head. Something was very wrong about this. Her previous encounters with hostiles had gone by with relative predictability; fight, loot, run. This time, however, something was different. Not only had he not killed her yet, he seemed almost.. _.familiar_ to her. There was something strange about his presence, like she should trust him somehow and her gut churned with discomfort. The name he'd supplied her stirred something deep in her subconscious but she couldn't quite put her finger on it.

Just who _was_ this man?

"Lower your weapon, please," he asked again, this time with a little more conviction, a curious emotion in his eyes that she had never seen before. His voice - the gruff timbre of it - caused goosebumps to erupt on her skin and she shivered at the sensation. Somewhere in the deep recesses of her mind, something called out to her. Muted and desperate, it was as though a part of her she didn't know existed was fighting to the surface of her consciousness.

"How do I know you're not a Synth?" Her voice cracked, hoarse from the lack of use, heavy with emotion, and she hated herself for it. She wasn't used to having conversations, she couldn't even remember the last time she spoke with anyone outside the handful of survivors from the Safehouse.

"I'm not a Synth, Beckett." The man released one hand from his gun, and held it up in the universal sign for 'I surrender'. His other hand disappeared behind his back as he tucked the gun into his holster. "Okay, I'm putting the gun away so you know I won't hurt you. I'm not a Synth, okay?"

"No, prove it." Her voice echoed around the empty room with far more confidence than she actually possessed. "Prove it or I'll kill you."

The man blinked at her, eyebrows furrowing. A strange warmth spread through her, fingertips tingling as he maintained his steady, silent gaze on her. Her sabre glows pink, the loud crackling reduced to a gentle hum.

"Your name is Kate Beckett," he said suddenly and the name...

 _Kate Beckett._

 _Her_ name. That was her _real_ name. She didn't know how she knew, but she did.

For so long since she woke up, she'd been yearning to find out what her real name was. _Who_ she was. The vague memories of a life long past haunted her in her dreams, continuously tormenting her with flashes of vibrant color, of a time when people were still... _people_. And now - now this strange man with his intense blue eyes was calling her Kate Beckett and looking at her as if he knew her.

The sense of validation sparks through her as the three syllables echoed in her head. Knowing that the name she'd been calling herself for so long was more than just a random string of letters sewn onto the blue jumpsuit she had woken up in - that it was her real name - it resonated with her, straight to her core.

Still, she thought as she refocused on the man before her, it didn't mean he could be trusted.

"That's not what I asked you."

"You have a scar," he declared. He lifted a gloved hand to point at his own chest. "Should be right about here. And don't - don't stab me with that sabre, okay? But I'm just going to show you that I have the same one. We'll match. And Synths don't scar. So..."

He trailed off, fingers pulling down the zipper of his leather jacket. There was a rip in the shirt he wore under the jacket and he pulled at the fraying edge to reveal the left side of his chest. An ugly scar, puckered and angry marred his otherwise unblemished skin.

Exactly like hers. The one she had no memories of getting.

Her blood thrummed in her veins, and couldn't contain the excitement bubbling beneath her skin. Her initial distrust for the man had all but disappeared and even though it went against everything she knew about survival, her heart screamed at her to trust him.

Wholly.

This Castle man _knew_ her.

She blinked as she looked at him, _really_ looked at him. He looked battle-worn, exhaustion etched into the hard lines of his face - a rather attractive face, inner voice supplied. Something about him...

It pleased her.

She took the three steps that separated them, stretching out so her fingers trailed down his chest, taking in the ridges of the scar and the warmth radiating from his skin.

Hope flared within her for the first time since the whole damn world had turned to ruins.

"Castle." The name flew off her tongue easily, curling around the consonants with ingrained familiarity.

 _Castle_

 _She's in a big room. A single man sits amidst the shelves of books, his back facing her, completely unaware of her presence._

" _Richard Castle! You are under arrest for felony theft and obstruction of justice!"_

 _The scene shifts and they're in a park, it's cold. Bright. Lots of colours. "I'm a one and done kind of girl," she hears herself saying._

 _Then she's in another room, wooden floors, glass windows. There's a murder board in front of her and it's him. He's staring back at her, sad, yet indignant as he says something she can't quite make out. But then she responds and her own words are as clear as day._

" _I'm a one writer girl."_

 _Everything hurts, her heart feels constricted and - she's on the ground - grass? She's on grass, and her tears are streaming down her cheeks. He looms overhead, yelling, begging for something, maybe - she can't hear him, the ringing in her ears drowning out the words he keeps repeating over and over again and suddenly-_

"Beckett, I love you."

Yanked out of the streams of memories assaulting her brain space, her heart beating a million times faster than usual, she found herself staring into his eyes, blinking, unable to comprehend just what she was experiencing.

"Beckett, I _love_ you," he repeated with more force behind his words. Castle in front of her spoke at the same time as the Castle in her memories and she gasped, pulling her hand away from him.

The weight of the memories was almost too much to bear, her brain barely able to keep up with the onslaught of scenes, conversations - like the floodgates had finally opened and everything she repressed since the Cull was fighting to break free of her self-imposed restraints. It was too much. Too much of her past life - too much...

Happiness.

Castle caught her as she wobbled on her feet and she fell into his embrace, clenching her eyes shut. She willed herself to calm down, regulating her breaths, and somehow - _somehow_ it worked.

She opened her eyes again, seeing him with newfound clarity, and she smiled.

" _Castle."_

* * *

Initially, I had every intention of this being multiple chapters, but I seem to have lost my muse recently so for now, this will remain a one shot.

Thank you for reading and I would really love your thoughts!

Twitter: estheryam  
Tumblr: griever11


End file.
